1.- CARACTERÍSTICAS Y TIPOLOGÍA

Box 8.1: Identification of dust sources in the West Asia region

A study was conducted by the Geoinformatic Research institute (GRi) of the University of Tehran on dust sources in West Asia to support the UNEP-coordinated Action Plan on Dust and Sand Storms for West Asia. The objectives were to (i) identify active dust storm sources in West Asia, (ii) characterize atmospheric patterns that result in dust storms, and (iii) investigate factors that contribute to the formation and intensification of dust storms activities.

identification of dust sources was done by determining factors of dust occurrences, using satellite images, atmospheric data, wind trajectory models, soil information, soil water holding capacity, and land cover data. To distinguish dust storms of regional significance from local storms, the following criteria were used to define regional events: (i) storms had to be recorded by at least three weather stations with a minimum distance about 100 km from one another, (ii) observation of widespread dust in suspension in the air, not raised by wind at or near the station at the time of observation (i.e., 06 WMO meteorological codes);

(iii) visibility has to be less than 1000 m, and (iv) the storm had to be recorded as independent event.

Most of the affected regions are located in a corridor stretching across West Asia.

Widespread dust storms were classified, based on the similarity in spatial distribution and atmospheric patterns, in three main clusters and one subsidiary cluster (intensifier). Cluster 1 consists of point sources between the Tigris and Euphrates rivers, stretching from Baghdad in the south to Ceylanpinar in the north and Mosel city in the east (see also Box 8.3).

Most activity is in the southern part of the cluster in iraq, where soil water holding capacity is higher and is therefore more prone to drought compared

with the north part in Syria. in addition, the southern part of the cluster is part of the Aljazeera desert, which is prone to erosion due to the natural deposits of salt and sandy alluviums from ephemeral rivers. Dust storm activity corresponds with drought periods and trends in water storage, for example especially during the drought of 2007-2008. Construction of hydraulic structures on the Tigris and Euphrates rivers poses severe risks to water storage downstream, and consequently to vegetation productivity and land susceptibility to dust storms in the future.

Cluster 2 is located in west and south west iraq, approximately coinciding with Al-Anbar province. Dust sources relocate towards the south from the northwest of iraq and the east of Syria (Cluster 1) into the Cluster 2 area and into the north of the Arabian Peninsula, especially in winter and spring. Apart from the north and

Dust storm corridor in West Asia. Source: Darvishi Boloorani et al. 2014.

Dust storm sources in West Asia, identified as three main clusters and one subsidiary cluster. Source: Darvi-shi Boloorani et al. 2014.

Box 8.1: Identification of dust sources in the West Asia region (continued)

Box 8.2: Dust storm hot spots in the Islamic Republic of Iran

plains produces soils that are susceptible to wind erosion. Analysis of atmospheric patterns on dusty days of Cluster 2 indicate considerable cyclone and anti-cyclone weather patterns leading to the creation of high speed winds and consequently dust storm formation.

Cluster 3 is located in east and south east Arabia. This area is bounded by the Rub-al

Khali desert in the south, the Emirates, Qatar and Bahrain in the east, and the Persian Gulf in the north.

Dust storms are mostly associated with rare weather events due to the convergence of easterly and westerly winds. Sandy soils constitute 84% of the land coverage resulting in low susceptibility to wind erosion.

The subsidiary cluster is located in southeast iraq with a small part in southwest iran. Dust sources in this area are activated simultaneously with other sources, making their dust clouds denser. Although silt soils, which are normally susceptible to wind erosion, cover 43% of the area, these soils have high water holding capacity, which reduces their susceptibility. A combination of drought periods and reduced water flow into marshland, and their over-utilization are contributing factors to increased SDS risk.

The analysis of dominant atmospheric patterns in every cluster shows that generally there are two main patterns favouring dust storms: the summer low pressure of the iran plateau and cyclonic and anti-cyclonic winter patterns. in common with the situation in many other regions, vegetation reduction, exacerbated by severe drought during the last decade, combined with significant areas of susceptible soils, has led to widespread dust storm formation within the region. Reduced water storage due to upstream water retention was identified as an important additional risk factor in this region.

Dust prognosis in the region could be improved by providing more detailed evidence on dust sources as input to numerical models, including also small-scale hot spots, and their seasonal variability. A start on this was made through the WMO SDS-WAS project “Dust forecast model inter-comparison: Case study of the dust storm over Tehran on 2nd June 2014”. This ongoing project, aims to better understand generation and development of small-scale dust storms and explore the potential to use this information to improve dust models so that they can more accurately simulate such events. Work is ongoing with geological survey specialists in the region to collate missing data on dust sources.

Source: Darvishi Boloorani et al. 2014.

A study of dust storm hot spots in iran was conducted by the Geoinformatics Research institute of the University of Teheran as an initiative to prioritise UNEP pilot study sites under the SDS West Asia Regional Action Plan, and to identify possible interventions.

in 2011, the population of iran was about 75 million, of whom 71% live in cities. There are large areas of the country with soils that are susceptible to wind erosion. Dust storms have emerged as a significant problem during the last decade, coinciding with droughts, and affecting a large portion of west and southwest iran. The fertile plain of Khuzestan province is one of the most highly populated regions, which has experienced the largest number of transboundary dust storms during the last decade.

The criteria for selection of hot spot pilot sites included trends in the frequency and severity of dust storm occurrence, representativeness of the ecological conditions and land degradation drivers, and capacity for implementation of interventions. Two main clusters of dust storm activity were identified, representing sources in both arid and humid areas.

in the southwest cluster, more than drought and scarcity of water resources, pressure has come from a population that is three times more than the ecological and pasture potential of the land. This has resulted in deforestation and land use changes, exacerbated by development projects and unsuitable cultivation practices. in the southeast cluster, problems identified included unsuitable cultivation methods, over-grazing and mismanagement of pastures, over-exploitation of woody vegetation, and upstream

Box 8.2: Dust storm hot spots in the Islamic Republic of Iran (continued)

interventions identified for pilot sites in the two clusters included developing capacity in sustainable agriculture and natural resources management, use of new energy sources to prevent cutting of trees and shrubs, institutional development, establishing monitoring and early warning systems, and adaptive research on appropriate solutions.

Source: Darvishi Boloorani (2014).

Two main clusters identified for pilot demonstration projects.

Source: Darvishi Boloorani (2014). Dust storm over the 2nd cluster identified as a pilot site. MODiS 22 February 2012.

Major land degradation processes in iran. Yellow areas show wind erosion, with darker colours indicating most severity. Source: Darvishi Boloorani (2014).

Number of dusty days in iran over a 20-year period from 1985 to 2005 (Mohamadkhan et al. 2016)

Box 8.3: Identification of dust sources in Iraq using satellite imagery

Dust sources in iraq were characterized using remote sensing products as part of the West Asia SDS Regional Action Plan. Dust storms are considered to be one of the most important environmental hazards in iraq and the region.

in the summer, iraq is affected by low pressure centred in the areas of the Arabian Sea and the indian Ocean, and the high pressure regions in the plateau of Anatolia, resulting in the Shamal winds in the north and northwest. From mid-June to mid-September this is accompanied by intensive heating of the land surface, causing dust storms to rise to heights of one kilometre. in recent years, the frequency of dust storms has increased in iraq and the surrounding areas due to drought, causing reduced vegetation cover and deterioration of soil quality. in Mosul, Baghdad and Basra the number of dust storm days increased from 1987 to 2002. There was a surprising increase in the number of dust storms in Baghdad.

Various remote sensing products are used to track dust storms and to help to identify their sources.

The SEViRi Meteosat second generation (MSG) images are used to monitor the path and spatial scales of dust storms. Their movement is monitored using true colour composite images supplied by Europe’s meteorological satellite agency, EUMETSAT.

The concentration of dust can be observed clearly from true colour red-green-blue (RGB) composites from the Moderate Resolution imaging Spectroradiometer (MODiS) from the Aqua and Terra satellites. The spatial resolution of 250 metres allows identification of point sources.

Contour map of dust storms for Mosul, Baghdad and Basra and for the period 1987-2002. Source: Abdulkareem et al. 2013.

Annual total precipitation rate for iraq for 1970-2008 show-ing a trend of decreasshow-ing rainfall. Source: Crook 2009.

Colour composite image showing a dust storm crossing iraq on 12 April 2011, computed from archived Meteosat-9 data.

Dust appears as magenta colour. Source: Alzubaidi et al. 2013.

identification of point sources (yellow dots) of a dust storm on 10 March 2012, using a MODiS colour composite.

Box 8.3: Identification of dust sources in Iraq using satellite imagery (continued)

HYSPLiT output for a dust storm on 3 March 2011 at 1500 UTC .

The Hybrid Single-Particle Lagrangian integrated Trajectory model (NOAA-HYSPLiT) is an atmospheric transport and dispersion model. it was developed by the Air Resources Laboratory (ARL) of NOAA. The HYSPLiT trajectory model provides information on simulated smoke plume (and dust) trajectories by tracking a parcel of air that is carried by the mean 3-D wind field derived from a numerical weather prediction model. it is being used to help track the sources of dust storms (Abed et al. 2012).

Finally, the different sources of information are combined with a MODiS image to show passive and active dust sources. Further ground investigation is then warranted to deduce the causes.

Source: Abdulkareem A. A. Mohammed, iraqi Ministry of Science and Technology.

MODiS image showing passive and active dust sources, produced by the US Naval Research Laboratory (NRL) and the National Oceanic and Atmospheric Administration (NOAA). Blue crosses show dust sources; black crosses show additional dust sources added by NRL; red crosses show dust sources not active since 2005.

Box 8.4: Assessment of Inorganic and Organic Characteristics of SDS Loads in Iraq

Dust storm distribution

The average annual number of days with dust storms across iraq for the period 1981 to 2011 indicated that Nasriya was the governorate with the highest frequency of dust storms, reaching 20 days/year.

Dust characteristics

The composition of dust from storms that reached cities in central and southern iraq was analysed. The total number of studied dust storms was 48 during 2007- 2010, 7 in 2007, 20 in 2008, 11 in 2009, and 10 in 2010.

Analyses of particle size distributions of dust storms provided information on: clay (20 - 71%, mean=55%), silt (18% - 63%, mean= 32%), and sand (8 - 18%, mean=13%) contents. The main texture of most dust samples was sandy silty clay (71.4%), and to lesser extent sandy clayey silt (28.6%), depending on the energy and velocity of the wind from the regional dust storm.

The following heavy minerals (1.3%) occurred in dust samples: opaque heavy minerals, pyroxene, hornblende, zircon, chlorite, epidote, and garnet. The following light minerals occurred in the dust samples: quartz (52.2 %), feldspar (6.4%), calcite (33%), gypsum (5.6%), and dolomite (1.5%). The roundness of quartz particles ranged from sub-rounded grade (82% of all the studied samples), to rounded grade (18% of all the studied samples), indicating a long distance of transportation.

The mineralogy of the clays in the dust samples were examined by X-ray diffraction (XRD). The clay minerals recognized were: chlorite, illite, montmorillonite, palygorskite, and kaolinite. The presence of palygorskite and kaolinite reflects the arid and semi-arid climatic conditions of the source areas. The presence of chlorite reflects arid and semi-arid conditions in an alkaline environment, while illite minerals are very common in desert soils.

Uranium concentrations (average absorbed dose and average external effective dose) were derived from dust samples of sandstorms from 2-4 July 2009 and 3-4 April 2010 at cities Baghdad and Ramadi. All the results were lower than critical dose level, but the accumulation of the dose from more than one sandstorm may have a damaging effect.

The mean concentration of trace metals in descending order were: Fe (2,940 ppm), Pb (43 ppm), Zn (375 ppm), Ni (154 ppm), Co (90 ppm), Cd (61 ppm), and Cu (56 ppm).

Pollen count frequencies, in descending order, were: Chenopodiaceous (80%), Graminea (68%), Pine (53%), Artemisia (40%), Palmae (18%), Olea (9%), and Typha (3%).

Microorganism frequencies in descending order were: gram-positive Bacillus species (49.3 %), Aspergillus species (18.6%), Candida albicans (10.8%), the negative rods Escherichia coli (9.5%), the gram-positive Cocci streptococcus pneumonia (8.7%), and the gram-negative rod Enterobacter Cloacae (4.4).

No viral isolates were found.

Source: Moutaz A. Al-Dabbas, College of Science, University of Baghdad Average annual number of days of dust storms across iraq,

using monthly means for the period 1981-2011 (iraqi Meteo-rological Organization 2013).

Box 8.5: Dust storm forecasting for human health - DuSNIFF

Related to the West Asia Regional Action Plan, a Dust Storm Network-based integrated system of Forecast and Forewarning system (DuSNiFF) is under development at the University of Tehran’s Geoinformatics Research institute (GRi). The system is able to operate at local to regional scales. DuSNiFF can provide information on dust AOD and content analysis, environmental indices, and health impacts, and provide forecasting, early warning, and public announcements.

Main components of the DuSNiFF forecast and forewarning system. Source: Geoinformatics Research institute, University of Tehe-ran.

Box 8.6: Controlled experiments on the impact of dust on plant and animal health

Laboratory experiments are being conducted under controlled conditions in the islamic Republic of iran to investigate the effects of dust particles on ornamental plants, crops, trees, and animals, Dust events are simulated using a wind tunnel and dust samples from current active sources in the country.

it was found that wheat (Triticum aestivum) has a high sensitivity to dust at the tillering stage (early phenological growth stage) compared with at heading stage. West Asia dust storms and especially in iran tend to occur at the early stages of wheat phenology, having an adverse effect on wheat yield. Leaf chlorophyll, biomass, nitrogen, and moisture content were affected.

Similar results were found in rosemary flower (Rosmarinus officinalis), tomato (Solanum lycopersicum), marigold (Calendula persica), violets (Viola odorata), strawberry (Fragaria ananassa), and oak seedlings (Quercus persica).

Control Exposed to Dust (1 to 6 days)

Fragaria ananassa

in another experiment two animal species including house mouse (Mus musculus) and rat (Rattus norvegicus) were exposed to simulated dust storms of different periods and concentration. in terms of lung disease, respiratory epithelium and hyperemia increased in both species. Bleeding (haemorrhage), inflammation and emphysema occurred in rats and pneumonia in house mouse. Edema (accumulation of water in tissue) and fibrosis were not affected by dust levels. Furthermore, dust led to a decrease in the number of white and red blood cells, and levels of alanine aminotransferase, aspartate aminotransferase, and other blood health indicators.

Effects of exposure of Fragaria ananassa plants to exposure to simulated dust storms of different periods (1, 2, 4 and 6 days; right) compared with the control (left).

Source: Darvishi Boloorani et al. (2015)

Lung emphysema, hyperemia, hemorrhage and inflammation in rat (Rattus norvegicus) exposed to simulated dust storms.

Box 8.7: Impact of preserved areas, farms and green belts on dust deposition in Kuwait.

Kuwait has high depositional rates of dust in its western, southern and northeastern regions as shown in the map below (Al-Dousari et al. 2016).

Control measures that have been tested include protected areas of native plants arranged in green belts, consisting of lines of tress of Prosopis and Tamarix species. in two preserved areas dust deposition was 40% to 76% less in downwind areas than in upwind areas. Farm areas reduced deposition by 88%. Green belts reduced dust by 26%. Native vegetation, green belts, and well-managed farms are recommended as the most practical method to mitigate dust problems in the region (Al-Dousari et al. in press).

Line plots showing dust deposition rates and reduction percentages (circles) in downwind areas compared to upwind areas for fenced areas (a) farms and fenced areas (b) and green belts (c).

Annual dust fallout in Kuwait 2010-2011

Source: Al-Dousari et al. (in press)

Box 8.8: China greening

China is one of the countries that is most seriously affected by desertification and SDS. The affected area covers 28% of the total land area and sandy desertification areas have expanded at the rate of 2,460 – 3,436 km² annually from 1990 to 2000. There are about 400 million people affected by desertification in China and eco-refugees have appeared in some regions due to desertification. The annual economic cost of desertification in China is estimated at CNY 128.1 billion (USD 19.8 billion), or about 1.4% of Chinese Gross Domestic Product (Tuo and Kebin 2006) and desertification has seriously affected regional economic and social development.

The China National Action Plan (NAP) to implement the UNCCD was drawn up in 1996 and revised in 2003. China is the first country to setup a national desertification monitoring initiative as a follow-up action. The Desertification Combating Law of China was drafted in 2001. For implementing the UNCCD, various bodies have been established, including: (i) the China National Committee for implementing the United Nations Convention to Combat Desertification (CCiCCD), (ii) the China National Desertification Monitoring Centre, (iii) the China National Training Centre on Combating Desertification, (iv) the China National Research and Development Centre on Combating Desertification, and (v) the Senior Experts Consultant Group in Combating Desertification. Related institutions for combating desertification have been setup in local provinces and autonomous regions.

The well-known programme “Combating Desertification Program in Blown-sand Source Area Around Beijing and Tianjin” and the “Green Great Wall” Programme cover more than 85% of Chinese desertified lands, forming the main body of the effort of the National Combating Desertification Programme.

Desertification monitoring of China consists of national monitoring, key (sensitive) regions and on-site monitoring, desertification project benefit monitoring and sandstorm monitoring. National Desertification Monitoring has been carried out five times since signing the UNCCD. The China Meteorological

Administration and State Forestation Administration are jointly in charge of SDS monitoring and forecasting. Many measures, such TV, newspaper, even cell phone message have been used in SDS forecasting and public awareness rising.

After 20 years hard work in combating desertification, the pattern of national desertification has reversed since 2004 and 1,280 – 1,720 km² of desertified land has been controlled. As a result, desertification severity has reduced significantly in recent years. This is a significant achievement towards implementing the UNCCD LDN initiative.

China is moving on with a new vision to extend its greening initiatives along the Silk Route, with an aim to plant 1.3 billion trees in ecologically vulnerable regions over the next 10 years. A Green Silk Road Fund was launched through public-private partnership in China.

Source: SFA (2013)

Trend of sandy desertification in China over the past 60 years.

Box 8.9: The Great Green Wall for the Sahara and the Sahel initiative

Africa is one of the continents most threatened by land degradation and desertification. The Sahara is the world’s largest single source of dust emissions and the Sahel is an area at high risk of increased wind erosion and anthropogenic emissions. in order to fight against land degradation, its impacts and

Africa is one of the continents most threatened by land degradation and desertification. The Sahara is the world’s largest single source of dust emissions and the Sahel is an area at high risk of increased wind erosion and anthropogenic emissions. in order to fight against land degradation, its impacts and